Structure of Earth

Question 1

3 layers of the Earth and distance

Answer 1

• Crust (0-100 km)
• Mantle (100-2900 km)
• Core (2900-6370 km)

Question 2

Layers of Mantle

Answer 2

• Top Layer: Lithosphere -> 0-100 km, solid (rigid), fused with crust.
• 2nd layer: asthenosphere -> 100-350 km, liquid, ductile.
• Bottom Layer: Mesosphere -> 350-2900 km, solid rigid.

Question 3

Layer of Core

Answer 3

• 1st core: Outer Core ->2900 -5100 km ,liquid
• 2nd core: Inner Core -> 5100-6370 km, solid

Question 4

Thickness of Crust

Answer 4

• Continental plate thicker (35 to 70km) “floats” high
• Oceanic plate thinner (6 to 10km) “floats” low

Question 5

Composition of Crusts

Answer 5

• Continental plate composed of Granite/Andesitic.
• Oceanic plate composed of Basaltic

Question 6

Density of Crusts

Answer 6

• Continental less dense (2.7 g/cm³)
• Oceanic more dense (3.0 g/cm³)

Question 7

Subduction of Crusts

Answer 7

• Continental does not subduct (too buoyant)
• Oceanic easily subducts

Question 8

Age of Crusts

Answer 8

• Continental plate older (<4.2 Ga (billion years)
• Oceanic plate younger (<200 Ma) Average age 65 Ma)

Question 9

Origin of Crusts

Answer 9

• Continental Plate -> Sea floor spreading.
• Oceanic plate -> volcaneos & accretions